Fluid feeder and pressure intensifier for automatic operation by using the initial pressure of the fluid fed itself



2,896,542 AUTOMATIC y 28, 1959 R. FORGHIERI FLUID FEEDER AND PRESSURE INTENSIFIER FDR OPERATION BY USING THE INITIAL PRESSURE OF THE FLUID FED ITSELF 2 Sheets-Sheet 1 Filed Nov. 15, 1956 w e 1 4 2 I/ i1 .III. M a gg gcc fi cfiE W u w M w M I 7 5 H w T- 5 M n M M w 5! v QI\ W 4? y? W um Q N. mu J! 0 v w a a 2 a Inventor.- Renaf/"o f orc hieri Jul 28, 1959 2,896,542 AUTOMATIC R. FORGHIERI FLUID FEEDER AND PRESSURE INTENSIF'IER FOR OPERATION BY USING THE! INITIAL PRESSURE OF THE FLUID FED ITSELF Filed NOV. 15, 1956 2 Sheets-Sheet 2 Invenfor:

k I m F 6 R BY "one compression stroke.

M 2,896,542" Patented July 28, 1959 FLUID FEEDER AND PRESSURE INTENSIFIER FOR AUTOMATIC OPERATION BY USING THE INITIAL PRESSURE OF THE FLUID FED ITSELF Renato Forghieri, Milan, Italy Application November 15, 1956, SerialNo. 622,441

Claims priority, application Switzerland November 18, 1955 6 Claims. (Cl. 103-50) The object of this invention is a fluid feeder and pressure intensifier provided for feeding a fluid and simultaneously intensifying its pressure in an automatic way, and by making use of the initial pressure of the fluid fed itself.

The purpose of this invention is to provide a device that is capable of feeding a fluid into a container or like apparatus, within which there is exerted a pressure that is greater than that of the fluid fed. This is for instance the case in coffee infusion preparing machines in which the water, with which the container is fed, is taken from the city water distributing plant and is sup plied to the boiler of such machines or other like apparatus under a predetermined pressure.

The device of this invention is characterised by two cylinders of different diameter and containing differentially acting pistons, and a feeding conduit for admitting the fluid to be fed under equal pressure to said cylinders so as to develop different forces acting upon the pistons that move therein, so that the piston in the larger pressure cylinder, that is submitted to a greater force, tends to compress the contents of the smaller pump cylinder. This causes an increase of pressure within the smaller cylinder the two pistons being connected for joint movement. The

fluid contained within the smaller cylinder is urged under the so increased pressure through a check valve into "a high-pressure conduit in order to feed the apparatus to be supplied with fluid under high pressure.

Suitably disposed compression springs are provided for recalling the pistons to their starting positions after each "Discharge valves release the pressure inthe pressure cylinder during its return stroke.

The communication between both cylinders is provided by a connecting conduit, which is supplied between the cylinder connections with the fluid to be compressed, so that the fluid is distributed to both cylinders in accordance with the pressure prevailing therein.

Said conduit may be an external one, and terminate in appropriate fittings of the cylinders, or it may be provided Within the connecting piston rod of the pistons that move within said cylinders.

.The apparatus of this'invention is illustrated by way of example by a specific embodiment in the annexed drawing, in which: 7 Figure 1 is a sectional elevational view of the fluid pressure intensifier of the invention taken on the axis thereof, and FigureZ shows a side elevation of the device of Fig. 1.

Referring now to the drawing, the fluid pressure intensifier comprises two cylinders 1 and 2, in which respective pistons 3 and 4 are reciprocablyslidable. Pistons 3 and 4 are rigidly connected by a common piston rod 5'sothat they move in unison. A conduit 6 connects the spaces of cylinders i and 2, and the inlet of each cylinder isprovided with a check valve 7 and 3, respectively, in order to feed the fluid to be compressed, which is supplied through a cock 9 mounted on fitting 10 inserted in said conduit 6. The check valves 7 and 8 allow passage of the fluid only in the direction from the conduit to said cylinder and prevent return of the fiuid to the conduit.

The top portion of cylinder 1 is provided with openings 11 through two of which a bar 12 is diametrically inserted. Bar 12 is provided with a sleeve 13 that surrounds the piston rod 5 to which it is fastened by a pin 14.

To the two ends of bar 12 there are fixed two rods 15 and 16, respectively, by means of nuts17- and 18, respectively, said rods projecting downwards in order to support at their lower ends a bridge 19 to which they are fixed by means of nuts 20 and 21.

Both rods 15 and 16 immediately beneath shaft 12 slidably pass through the brackets 22 and 23 that are fixedly fastened to the cylinder 1 and serve as supporting means for the springs 24 and 25 that surround the rods 15 and 16, respectively, Springs 24 and 25 abut with their bottom ends against the bridge 19 by means of small metallic blocks 26- and 27. The springs urge piston 3 to move downward.

The head of cylinder 1 is formed by a plate 28 fixed to it by means of screws 29, and is provided with two openings forming two conical valve seats with which the valve heads 30 and 31, respectively, cooperate to form valve means for connecting the cylinder 1 with two discharge conduits 32and 33, respectively. The stems 38, 39 of these valves traverse said conduits and pass through cylindrical propections 34 and 35 of said conduits and extend to the bridge 19 through the bores 36 and 37 of which they pass slidably.

In their middleportion the stems 38 and 39 of the valves carry fixed small cylindrical cups 40 and 41, the cavity of which is wider than the cylindrical projections 34 and 35 so as to allow the positioning of the ones over the others. Said cups support springs 42 and 43, respectively, that abut with their free ends against small cups 44 and 45 which in turn abut against bridge 19. The purpose of said springs is to urge valve heads 30 and 31 towards the open position thereof against pressure exerted within the cylinder.

The springs are dimensioned in such a manner that the spring force proportionally increases with said pressure so that they are capable of opening the valves when the piston 3 has reached the end of its upward stroke.

In this way, the opening of said valves releases the pressure existing invthe cylinder, and permits the return stroke downwards of the piston to be actuated by the springs 24 and 25 that had been compressed during the upward stroke of the piston.

The cylinder head of cylinder 2 is formed by a plate 46 provided with an axial opening which is sealed by a check valve 47 which is urged by spring as into the closed position so as to seal said cylinder-from the conduit 49 that has to be fed with fluid under increased pressure. When the fluid in cylinder 2 is compressed by piston 4 to a predetermined pressure, valve 47 permits the passage of thefiuid from the cylinder 2 to the eonduit 49. r

The aforeedescribe'd device operates as follows:

Starting from empty cylinders, and with the pistons in the .position'shown in the drawing, upon opening of the cock9, the fluid traverses both branches of the :duct 6 and enters 'the cylinders 51 and 2 through respective check valves 7 and 8.

Valves 3t) and 31 and valve 47 being closed, the cylinders are filled up with fluid and are subjected to its pressure. The filling up being done, valve 8 closes and a difference of thrustis*establishedbetweenthe pistons 3 and 2, by which piston 3, thatis subjected to a greater thrust, due to its greater diameter, is urged upwards takingalong the'p'iston' t that is rigidly connected to it. If the fluid is a liquid, there takes place an immediate increase of pressure within cylinder 2.

Thus the Contents of the cylinder 2 is forced through the valve 48 into the conduit 49 at a pressure that is much greater than the supply pressure of the fluid admitted through cock 9.

Piston 3 during its upward movement also takes along the bar 12 which freely moves in the openings 11, and thus rods 15 and 16 and the bridge 19, thereby compressing springs 24 and 25 and also springs 42 and 43 which, at the end of the upward stroke of piston 93, open the valves and 31 to release the pressure within the cylinder 1 by discharging the fluid contained in said cylinder through the conduits 32 and 33, whilst springs 24 and 25 expand and return the piston in a downward stroke to its starting position.

At this instant, valve 7 that has opened during the downstroke of piston 3 admits more water to cylinder 1 thus bringing the pressure back to its former value. In the same time more water enters cylinder 2, due to the pressure drop that has taken place during the downward stroke of piston 4 and has opened valve 8, whereupon the working cycle may be repeated.

As it may be seen from the above description, the fluid pressure intensifier operates by making use of the pressure of the supply fluid to urge a portion of said fluid into a conduit at increased pressure.

What I claim is:

l. A fluid pressure intensifier comprising, in combination, a pump cylinder; apressure cylinder having a cross section greater than that of said pump cylinder; a pump piston located in said pump cylinder reciprocably be tween fluid-receiving and fluid-discharging positions; a pressure piston located in said pressure cylinder reciprocably between fluid-receiving and fluid-discharging positions; motion-transmitting means connecting said pistons for joint simultaneous movement in such a manner that when said pressure piston is in fluid-receiving position said pump piston is in fluid-discharging position, and viceversa; a discharge valve in said pressure cylinder; first resilient means yieldingly linking said discharge valve to said motion-transmitting means for actuation thereby in such a manner that said discharge valve is open when said pressure piston reaches its fluid-receiving position; and second resilient means linking said pressure cylinder to said motion-transmitting means for permanently urging said pressure piston from its fluid-receiving into its fluid-discharging position.

2. A fluid pressure intensifier comprising, in combination, a pump cylinder; a pressure cylinder having a cross section greater than that of said pump cylinder; a pump piston located in said pump cylinder reciprocably between fluid-receiving and fluid-discharging positions; a pressure piston located in said pressure cylinder reciprocably between fluid-receiving and fluid-discharging positions; a common piston rod fixedly connecting said pistons for joint simultaneous movement in such a manner that when said pressure piston is in fluid-receiving position said pump piston is in fluid-discharging position, and vice-versa; a discharge valve in said pressure cylinder; first resilient means yieldingly linking said discharge valve to said motion-transmitting means for actuation thereby in such a manner that said discharge valve is open when said pressure piston reaches its fluid-receiving position; and second resilient means linking said pressure cylinder to said common piston rod for permanently urging said pressure piston from its fluid-receiving into its fluid-discharging position.

3. A fluid pressure intensifier comprising, in combination, a pump cylinder; a pressure cylinder having a cross section greater than that of said pump cylinder; a pump piston located in said pump cylinder reciprocably between fluid-receiving and fluid-discharging positions; a pressure piston located in said pressure cylinder reciprocably between fluid-receiving and fluid-discharging positions; motion-transmitting means connecting said pistons for joint simultaneous movement in such a manner that when said pressure piston is in fluid-receiving position said pump piston is in fluid-discharging position, and vice-versa; a discharge valve in said pressure cylinder; a rigid connecting member fixedly fastened to said motion transmitting means for joint reciprocating movement with said pistons; first resilient means mounted between said valve and said connecting member for urging said valve into the open position thereof when said pressure-piston approaches its fluid-discharging position; and second resilient means linking said pressure cylinder to said motion transmitting means for permanently urging said pressure piston from its fluid-receiving into its fluid-discharging position. 7 g V V 4. A fluid pressure intensifier'comprising, in combination, a pump cylinder; a pressure cylinder having a cross section greater than that of said pump cylinder; a pump piston located in said pump cylinder reciprocably between fluid-receiving and fluid-discharging positions; a pressure piston located in said pressure cylinder reciprocably between fluid-receiving and fluid-discharging posi tions; motion-transmitting means connecting said pistons for joint simultaneous movement in such a manner that when said pressure piston is in fluid-receiving position said pump piston is in fluid-discharging position, and vice-versa; a discharge valve in said pressure cylinder; first resilient means yieldingly linking said discharge valve to said motion-transmitting means for actuation thereby in such a manner that said discharge valve is open when said pressure piston reaches its fluid-receiving position; abutment means fixedly fastened to said pressure cylinder; a rigid connecting member fixedly fastened to said motion transmitting means; and second resilient means compressibly mounted between said abutment means and said connecting member for permanently urging said pressure piston from its fluid-receiving into its fluid-discharging position.

5. A fluid pressure intensifier comprising, in combination, a pump cylinder; a pressure cylinder having a cross section greater than that of said pump cylinder; a pump piston located in said pump cylinder reciprocably between fluid-receiving and fluid-discharging positions; a pressure piston located in said pressure cylinder reciprocably between fluid-receiving and fluid-discharging positions; a common piston rod fixedly connecting said pistons for joint simultaneous movement in such a manner that when said pressure piston is in fluid-receiving position, said pump piston is in fluid-discharging position, and vice-versa; a discharge valve in a wall of said presder; a rigid connecting member fixedly fastened to said piston rod for joint reciprocating movement with said pistons; first spring means mounted between said valve and said connecting member for urging said valve into the open position thereof when said pressure piston approaches its fluid-discharging position, abutment means fixedly fastened to said pressure cylinder; and second spring means compressibly mounted between said abutment means and said connecting member for permanently urging said pressure piston from its fluid-receiving into its fluid-discharging position.

6. A fluid pressure intensifier comprising, in combination, a pump cylinder; a pressure cylinder having a cross section greater than that of said pump cylinder; a pump piston located in said pump cylinder reciprocably between fluid-receiving and fluid-discharging positions; a pressure piston located in said pressure cylinder reciprocably between fluid-receiving and fluid-discharging positions; at common piston rod fixedly connecting said pistons for joint simultaneous movement in such a manner that when said pressure piston is in fluid-receiving position, said pump piston is in fluid-discharging position, and vice-versa; a discharge valve in a wall of said pressure cylinder transverse to the direction of movement of said pressure piston and opposite said piston rod; first 5 a 6 yoke means fixedly and transversely fastened to said pis said abutment means and said yoke means for permaton rod and extending laterally beyond said pressure cylinnently urging said pressure piston from its fluid-receiving der, at least two connecting rods extending parallel to into its fluid-discharging position.

the axis of said pressure cylinder from said first yoke beyond said transverse wall; second yoke means linking 5 References Cited in the file of this P the free ends of said rods; first spring means mounted be- UNITED STATES PATENTS tween said valve and said second yoke means for urging said valve into the open position thereof when said pres- 1 g 13 sure piston approaches its fluid-discharging position; abutf 64 c e 1942 ment means fixedly fastened to said pressure cylinder; 10 a my and second spring means compressibly mounted between 

